The lights I use are very powerful and are 4' fixtures with 6 T-5HO tubes. I use these fixtures mainly to supplement fall/winter light in my two greenhouses. A regular T-5 fixture would be fine for starting your seedlings. Though some swear by heat mats, I only use them if I am starting seeds in the greenhouse during the winter months. The temperature in those greenhouses is suppose to stay at 55F and above, but to start seeds, plumeria or any other, I would like to have the heat at least 70F or above. Thus the use of heat mats. It just depends on your growing conditions, Mary.
